Border cells are entorhinal neurons that are border-sensitive, reacting when a border is present in the proximal environment. Cells with such firing characteristics were predicted by Neil Burgess in 2000, and detected in December 2008, according to a single report by the group of scientists that had discovered the grid cells in 2005.[1] According to authors, border cells comprise about 10% of local population, being intermingled with grid cells and head-direction cells in the medial entorhinal cortex and para-subiculum.